It's not often that a man who has been in the same job for more than five years gets to do something new, but George W Bush has just managed it twice in 24 hours.

Mr Bush got a cordial reception, not an enthusiastic one

The first opportunity came on Wednesday afternoon, when, for the first time, he exercised his right to veto a bill that had been approved by both houses of Congress.

The bill would have lifted a ban the president himself placed on government funding for most research on embryonic stem cells, which many scientists believe could lead to treatment for serious diseases.

The following morning, Mr Bush addressed the annual conference of the National Association for the Advancement of Colored People - the nation's leading African-American civil rights organisation.

He had turned down their invitations since becoming president, and looked like he could become the first sitting president since the 1920s to refuse to address the NAACP.

But two short days before the event his spokesman had announced that he would do so for the first time since he was a candidate for president back in 2000.

Difficult ride

In typical fashion, he confronted the controversy head-on with a joke as he began his speech.

He praised the courtesy of NAACP leader Bruce Gordon, who had introduced him, adding: "I thought what he was going to say was, 'It's about time you showed up'."

When Bill Clinton was here, there was a lot more applause - but he had a record behind him

Courtney Patterson, NAACP delegate

The audience laughed, and cheered when he followed up with: "And I'm glad I did."

But Mr Bush got a more difficult ride for the rest of his 30-plus-minute speech, including a murmur of dissent when he said he came from a family that supported civil rights, and outright boos when he talked about charter schools.

He tried to link his support for religious organisations to the groups that fought for civil rights and was met with stony silence.

Courtney Patterson, a convention delegate from North Carolina, said he came to the president's speech with an open mind - and left disappointed.

"There were a lot of things in his speech that indicate he's not abreast of the real problems of the African-American community," Mr Patterson said.

"There were no specific commitments. How are you going to do the things you promise? What specific policies will you put in place?" he demanded.

Speaking to the BBC as the president's speech ended, he characterised the standing ovation Mr Bush received as "cordial".

"When Bill Clinton was here, there was a lot more applause - but he had a record behind him," Mr Patterson said of the former president.

Electoral considerations

Gerald Martin, an NAACP activist from northern California, said political considerations had forced Mr Bush to come address the organisation at last.

"I expect his advisers told him he couldn't be the only president in 80 years not to address the convention," Mr Martin said.

Mr Martin said it was best for Republicans that Mr Bush came

"It's in his best interests, and in the best interests of the Republican party."

African-Americans overwhelmingly vote for Democrats. Only one in ten voted for Mr Bush in 2000 and 2004.

Mr Bush acknowledged that in his speech, pointing out that the first Republican president was the man who ended slavery in the United States.

"I consider it a tragedy that the party of Abraham Lincoln let go of its historic ties to the African-American community," he said.

"For too long my party wrote off the African-American vote and many African-Americans wrote off the Republican Party."

But Carol Swain, a political scientist at Vanderbilt University in Nashville, Tennessee, said Mr Bush could not turn things around with a single speech.

"It's too late into his presidency to expect to neutralise how African-Americans feel about the Republican party," she argued.

She said he would have to make a truly grand gesture if he wanted his party to win African-American votes - apologise for slavery.

"He's the born-again Christian, he should be the one to press Congress to pass bipartisan legislation that would be a national apology for slavery," she said.

"It's the right thing to do at this point in history. For some African-Americans it would persuade them to vote for the Republican party."